1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef __PIDFD_H
4 #define __PIDFD_H
5 
6 #define _GNU_SOURCE
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <sched.h>
10 #include <signal.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <syscall.h>
15 #include <sys/mount.h>
16 #include <sys/types.h>
17 #include <sys/wait.h>
18 
19 #include "../kselftest.h"
20 
21 #ifndef P_PIDFD
22 #define P_PIDFD 3
23 #endif
24 
25 #ifndef CLONE_PIDFD
26 #define CLONE_PIDFD 0x00001000
27 #endif
28 
29 #ifndef __NR_pidfd_open
30 #define __NR_pidfd_open -1
31 #endif
32 
33 #ifndef __NR_pidfd_send_signal
34 #define __NR_pidfd_send_signal -1
35 #endif
36 
37 #ifndef __NR_clone3
38 #define __NR_clone3 -1
39 #endif
40 
41 #ifndef __NR_pidfd_getfd
42 #define __NR_pidfd_getfd -1
43 #endif
44 
45 /*
46  * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
47  * That means, when it wraps around any pid < 300 will be skipped.
48  * So we need to use a pid > 300 in order to test recycling.
49  */
50 #define PID_RECYCLE 1000
51 
52 /*
53  * Define a few custom error codes for the child process to clearly indicate
54  * what is happening. This way we can tell the difference between a system
55  * error, a test error, etc.
56  */
57 #define PIDFD_PASS 0
58 #define PIDFD_FAIL 1
59 #define PIDFD_ERROR 2
60 #define PIDFD_SKIP 3
61 #define PIDFD_XFAIL 4
62 
63 int wait_for_pid(pid_t pid)
64 {
65 	int status, ret;
66 
67 again:
68 	ret = waitpid(pid, &status, 0);
69 	if (ret == -1) {
70 		if (errno == EINTR)
71 			goto again;
72 
73 		return -1;
74 	}
75 
76 	if (!WIFEXITED(status))
77 		return -1;
78 
79 	return WEXITSTATUS(status);
80 }
81 
82 static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
83 {
84 	return syscall(__NR_pidfd_open, pid, flags);
85 }
86 
87 static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
88 					unsigned int flags)
89 {
90 	return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
91 }
92 
93 static inline int sys_pidfd_getfd(int pidfd, int fd, int flags)
94 {
95 	return syscall(__NR_pidfd_getfd, pidfd, fd, flags);
96 }
97 
98 static inline int sys_memfd_create(const char *name, unsigned int flags)
99 {
100 	return syscall(__NR_memfd_create, name, flags);
101 }
102 
103 #endif /* __PIDFD_H */
104